如何将服务返回的数据作为子组件的输入传递？角度2

I am trying to pass data that I am getting from my service call to the input of my child component but its always undefined or null. I have figured out the reason but don't know how to solve. The reason in my opinion is when the child component is rendered, the (uninitialized) variable is not yet set by the HTTP call so it gets passed uninitialized.I am trying to pass data that I am getting from